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[Federal Register Volume 89, Number 247 (Thursday, December 26, 2024)]
[Rules and Regulations]
[Pages 104888-104889]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-30568]

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DEPARTMENT OF HEALTH AND HUMAN SERVICES

42 CFR Part 73

Select Agent: Modified Jun[iacute]n Virus Vaccine Strain

AGENCY: Centers for Disease Control and Prevention (CDC), Department of 
Health and Human Services (HHS).

ACTION: Notification of determination.

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SUMMARY: The Centers for Disease Control and Prevention (CDC), located 
within the Department of Health and Human Services (HHS), has 
determined that a previously excluded attenuated strain, Jun[iacute]n 
virus vaccine strain Candid No.1, has key attenuating mutations in the 
glycoprotein envelope at GP1 T168A and GP2 F427I. Revertants at either 
of these positions have increased pathogenicity and virulence. 
Therefore, Jun[iacute]n virus vaccine strain Candid No. 1 containing 
GP1 168T and/or GP2 427F is a select agent and is subject to the select 
agent and toxin regulations.

DATES: This determination is applicable as of May 3, 2024.

FOR FURTHER INFORMATION CONTACT: Daniel A. Singer, MD, MPH, FACP, 
Acting Director, Division of Regulatory Science and Compliance, Centers 
for Disease Control and Prevention, 1600 Clifton Road NE, Mailstop H21-
4, Atlanta, Georgia 30329, Telephone: (404) 718-2000.

SUPPLEMENTARY INFORMATION: Jun[iacute]n virus is a negative sense, 
double stranded RNA virus and is the causative agent of Argentine 
hemorrhagic fever. Jun[iacute]n virus causes chronic infection in 
Calomys musculinus, the Drylands vesper mouse. Humans can become 
infected upon exposure to infected animals or infected animals' waste. 
Human-to-human spread is rare but can occur upon contact with an 
infected person's bodily fluids.
    In accordance with the Public Health Security and Bioterrorism 
Preparedness and Response Act of 2002 (Bioterrorism Response Act), HHS 
regulates biological agents and toxins that have the potential to pose 
a severe threat to public health and safety (42 U.S.C. 262a(a)(1)). The 
list of HHS select agents and toxins is provided in the HHS select 
agent and toxin regulations (42 CFR part 73) and Jun[iacute]n virus, a 
South American hemorrhagic fever virus, is included as a select agent 
(42 CFR 73.3(b)).
    The HHS select agent and toxin regulations established a process by 
which an attenuated strain of a select biological agent that does not 
have the potential to pose a severe threat to public health and safety 
may be excluded from the requirements of the select agent and toxin 
regulations (42 CFR 73.3(e)). On February 7, 2003, Jun[iacute]n virus 
vaccine strain Candid No.1 was excluded from the regulations as it does 
not pose a significant threat to public health and safety (McKee KT Jr, 
Oro JG, Kuehne AI, Spisso JA, Mahlandt BG. ``Candid No. 1 Argentine 
hemorrhagic fever vaccine protects against lethal Jun[iacute]n virus 
challenge in rhesus macaques'' Intervirology. 1992: 34(3):154-63). This 
exclusion was granted based on the historically safe use of this strain 
as a vaccine against Argentine hemorrhagic fever for

[[Page 104889]]

agricultural workers at risk of occupational exposure in Argentina.
    As set forth under 42 CFR 73.3(e)(2), if an excluded attenuated 
strain is subjected to any manipulation that restores or enhances its 
virulence, the resulting select agent will be subject to the 
requirements of the regulations. CDC's Intragovernmental Select Agents 
and Toxins Technical Advisory Committee (ISATTAC), which comprises 
federal government subject-matter experts from HHS, the U.S. Department 
Agriculture, the Department of Homeland Security, the Environmental 
Protection Agency, and the Department of Defense, reviewed the data 
published in the study, ``Restoration of virulence in the attenuated 
Candid No.1 vaccine virus requires reversion at both positions 168 and 
427 in the envelope glycoprotein GPC'' (published in the Journal of 
Virology [https://doi.org/10.1128/jvi.00112-24] on March 20, 2024). The 
ISATTAC concluded that the modified strains (Candid No.1 containing GP1 
168T and/or GP2 427F) showed an increased virulence compared to the 
parental excluded Candid No.1 strain when injected into guinea pigs and 
huTfR1 mice. CDC concurred with the ISATTAC's assessment and, on May 3, 
2024, CDC determined that given the restoration of virulence, 
Jun[iacute]n virus vaccine strain Candid No.1 containing GP1 168T and/
or GP2 427F is a select agent and is subject to the select agent and 
toxin regulations in accordance with 42 CFR 73.3(e)(2).

    Dated: December 18, 2024.
Xavier Becerra,
Secretary, Department of Health and Human Services.
[FR Doc. 2024-30568 Filed 12-23-24; 8:45 am]
BILLING CODE 4163-18-P
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